I don’t know what, precisely, Obama has done (or attempted to do, but I’ll address that in a moment) vis-a-vis employment, or what he or Romney intend to do in the next four years. But:
Candidate Jeremy Stevenson intends to create incentives for companies to hire in the U.S. Tax breaks, regulatory variences, that sort of thing. Candidate Walter Goldwater intends to pursue policies that have the effect (intentional or otherwise) of creating incentives for companies to send jobs overseas. Which is better for un- or underemployed people? Which is more likely to be good for a specific individual?
More generally, Candidate Stevenson believes government has the authority, ability, and responsibility to actively encourage job creation. Candidate Goldwater, to put it briefly, does not. Which is better for un- or underemployed people? Which is more likely to be good for a specific individual?
So getting back to the actual, non-hypothetical candidates, if Obama’s attempts to boost employment have largely been rebuffed – and I doubt many of us would want the president to have the dictatorial powers necessary to avoid that – it’s difficult to say that his policies have failed; the worst I think one could really defend is that they haven’t succeeded. Most of what you see around you is not the results of the failed policies of the Obama administration but of the absense of the untried policies of the Obama administration. I’m not sure those policies would work, but there’s no evidence they haven’t.
Also, what has Romney said or done that makes you think he would be better? Do you have any reason to assume Romney would be better, other than that he’s not Obama? That’s not a rhetorical question.
As for what you literally asked, I understand the contention is not that the Obama administration directly did much to foster job growth, only that they generated economic improvements which led to job growth. And it turns out a rising tide only lifts some boats.
If everyone voted on the basis of (perceived) self-interest, the winner would be the candidate perceived to be best for a plurality of the electorate.
Also, if he’s so skilled at creating jobs as a businessman, shouldn’t we let him stick to what he’s good at? That doesn’t necessarily translate to doing it as president.